A conventional vacuum sealing machine contains a movable arm disposed at a central position of a vertical plate on a rear side of a base of the vacuum sealing machine, and the movable arm swings and axially couples with a press bar so as to move with the press bar. The press bar has two sides connecting with a cylinder pillar so that the press bar returns back to an original position automatically. The movable arm has a nozzle cylinder fixed on a bottom end thereof and moving frontward and backward, and a forced lever has a wire secured therein and a heat-resistant cloth covered therearound. Thereby, the sealing machine seals a plastic bag by using the tee movable arm and the press bar. However, a length of the press bar is fixed, so an elongated plastic bag cannot be sealed, and the user has to replace another press bar with a longer length so as to seal the elongated plastic bag, thus having a complicated operation. In addition, the press bar with the longer length will increase a receiving space of the sealing machine.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.